几种网络RTK技术的比较分析

针对网络RTK技术在各个领域广泛应用的几种关键技术,介绍了当前各种技术的原理,并逐一进行了比较分析。采用误差综合的方法推导VRS的定位模型,提出主辅站采用邻近全网基线解算的技术优势。认为应合理选取建设哪一种网络RTK服务,系统的管理维护和系统兼容性是未来网络RTK研究领域的重点问题。     

网络RTK技术在高速公路登记测量中的应用

结合实例,阐述网络RTK技术的系统组成和基本原理;对常规RTK技术与网络RTK技术进行了比较;介绍网络RTK测量中三种几何精度检验的方法。     

基于GPS网络技术分析与应用研究

GPS网差分定位精度达厘米级的手持RTK系统已出现在市场,并且能够采用无线通信技术进行RTK数据差分源传输。本文对单基站、多基站CORS系统以及手持RTK系统的技术构建过程进行介绍。并通过实验,对三种GPS网络技术的成熟,使网络RTK成为测绘领域的研究热点。最后,与基准站连接实时优点进行比较,并提出有益建议。     

福建省连续运行参考站网络的构建

CORS系统是构建网络RTK的基础,首先阐述了CORS的发展历史,介绍了网络RTK所采用的主要系统服务技术,对比了网络RTK相对于常规RTK具有鲜明的技术特点和诸多优势,对CORS系统的精度分析说明了CORS网络的单日解算精度完全可以满足一般的工程项目控制数据和矿区地面沉陷监测的精度要求,经过长期观测数据累计,CORS网络可以满足并应用于更高精度要求的测量项目。     

南方CORS系统在数字化测图中的应用

随着RTK技术在数字化测图方面的应用日益广泛,但对地形复杂测区,普通RTK技术常遇到诸多问题,造成作业效率低下。而CORS系统中的网络RTK技术是GPS-RTK技术进一步延伸,采用网络通讯大大延伸了RTK的作业半径,提高了定位精度和可靠性,以工程项目为例,详细介绍了网络RTK技术在数字化测绘中的应用。     

基于CORS系统的网络RTK技术在城镇地籍测量中的应用

介绍了CORS的基本原理及基本结构,通过实例分析了基于CORS系统的网络RTK技术在地籍测绘生产中的优势,研究了基于CORS系统的网络RTK定位精度的评定方法。结果表明,利用基于CORS系统的网络RTK技术进行测绘生产的方法科学、精度可靠。证明了基于CORS系统的网络RTK技术在测绘生产中具有广阔的应用前景。     

网络RTK技术发展与应用

系统介绍了网络RTK测量技术的原理,分析了连续运行参考站系统（CORS）技术构成、数据通讯方式等,比较了网络RTK中虚拟参考站（VRS）技术和主辅站技术（MAC）的工作原理和基本流程,展望了基于陆态网络移动参考站的网络RTK技术的应用前景。     

VRS技术原理及网络RTK在城市规划测量中的应用

哈尔滨市GNSS双星导航系统正式建成并投入使用,其网络RTK的基本原理是通过虚拟参考站(VRS)技术进行超短基线的实时差分GPS测量,进而获得较高精度位置信息.系统网络RTK覆盖面积达1.4万km<'2>,和传统RTK测量技术相比较,网络RTK有覆盖范围广、精度高、易于操作等优点,在城市规划测量中得到了广泛的应用.     

网络RTK技术在像控测量中的应用研究

分析了常规RTK在像控测量中的不足和网络RTK技术的优点,并在常州市航测项目中采用了网络RTK技术进行像控测量,实现了网络RTK技术在像控测量领域的研究和推广应用。     

几种形式的网络RTK技术比较与应用研究

目前,网络RTK成为工程领域的研究热点.但是,许多城市还没有建立当地的CORS系统,或者仅有单基站系统.因而,对于测绘工程领域来说,网络RTK技术仍是该地区的最大需要.于此同时,高达10 cm的实时定位精度的手持机已经进入测量市场,称之为手持RTK当之无愧.本文就单基站CORS技术与网络CORS技术,以及手持机连接自设基站技术测量精度进行分析与比较,并提出有益建议.     

阿克苏河-塔里木河水系水质污染遥感监测与评价

 采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的 污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体 污染变化曲线,得出污染物浓度随着远离上游而增加。     

Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data

The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw.     

使用FME与VBA提取机场方格网高程数据

因受机场工程设计软件的测量数据容量限制,基于LiDAR采集、点云分类后得到的地面点云数据LAS不能完整应用于目前设计软件进行设计计算。本文通过对拟选技术方案的筛选,提出了利用FME Workbench数据处理功能,结合VBA编程获取外部方格网平面数据的方法。该方法在FME Workbench中实现了地面点云数据构建TIN、采用逐点内插方法从TIN中提取方格网高程数据、等高线生成及相应图形处理与成果输出。最终通过实际算例证明了该方法的有效性。     

Landslide risk analysis between Giri and Tons Rivers in Himachal Himalaya (India)

The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies.     

Gravity Changes Before Large Earthquakes in China: 1998-2005

Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200...     

GNSS系统及其技术的发展研究

阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议.     

自动车辆定位导航系统中传感器的误差分析

对国界定位导航系统中几种常见的辅助传感器所产生的误差进行了分析，导出了不同传感器的误差模型。这些误差模型是估计车辆位置的扩展卡尔曼滤波器的基础，同时也为选择适当的传感器提供了理论根据。     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Virtual Australia: its key elements – know,think, communicate

Abstract

Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised.